<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <title>Document</title>
</head>

<body>
  <div id="app">
    <h2>{{firstName + ' ' + lastName}}</h2>
    <h2>{{firstName}} {{lastName}}</h2>

    <h2>{{getFullName()}}</h2>

    <h2>{{fullName}}</h2>

    <h2></h2>

  </div>

  <script src="../js/vue.js"></script>
  <script>
    const app = new Vue({
      el: '#app',
      data: {
        firstName: 'Lebron',
        lastName: 'James'
      },
      computed: {
        fullName: function () {
          return this.firstName + ' ' + this.lastName;
        }
      },
      methods: {
        getFullName: function () {
          return this.firstName + ' ' + this.lastName;
        }
      }
    })
  </script>
</body>

</html>